Hydrophone Hunting (tutorial)

Alcibiades · 04-08-10, 10:29 AM

Hunting a target with the hydrophone. Using 100% realism (no map contacts)

I asked for help with this a few days back and since have been having a blast with it. Picking up the sound of a target's 'whoop whoop' of the propeller well beyond visual range - plotting their course, moving to PERFECT intercept location.... all while well beyond visual range. Then waiting while they slowly come into view right along their pre-plotted "path" and into the sights, 500m away. Fun!

Anyway, I made these two PDF files with 15 steps to illustrate how to track a ship with the hydrophones. I originally made them for myself, to help with understanding how it works - but figured I'd share them as they may be helpful for others. They are designed to be a simple step-by-step guide that can be easily printed.

They require a basic understanding of how to use the drawing tools for in-game plotting.

(edit) noticed some are missing S2. Be sure you download BOTH sheets. The first (S-1) has steps 1-8 and plots heading. The second (S-2) has steps 9-15 and shows how to get speed and distance.

SHEET 1
http://www.filefront.com/16063311/Hy...cking%20S1.pdf

and

SHEET 2
http://www.filefront.com/16063315/Hy...cking%20S2.pdf

Also, I sure as heck didn't invent this stuff - I just learned it a few days ago. Most helpful to me was the video by nefeldamon on the SHIII forum. I'd suggest checking it out also if you have the time. (the PDF files are based in concept around his example) http://www.subsim.com/radioroom/showthread.php?t=154461

And again big thanks to Kylania for pointing me to his video in the first place and also helping me find a site where I could upload the PDF files.

Hope this is helpful to anyone else who may want to try this.

Capt_Sluggo · 04-08-10, 11:25 AM

Thank you, Alcibiades! This will be a lot of fun. Less dangerous than visual hunting, too.

gutted · 04-08-10, 01:24 PM

Ahem:
http://www.subsim.com/radioroom/showthread.php?t=167103

^ Once you lean the basics... you can stop drawing all those nasty lines. Post #12, shows a step by step using it.

Alcibiades · 04-08-10, 02:14 PM

Quote:

Originally Posted by gutted

Ahem:
http://www.subsim.com/radioroom/showthread.php?t=167103

^ Once you lean the basics... you can stop drawing all those nasty lines. Post #12, shows a step by step using it.

Yes, I agree that your program can take all the 'work' out of it. You did a heck of a job making that program. And it looks pretty nice

- but that is the part I find fun

. Maybe I'm weird and I just like drawing lines and circles

. I could also just turn map contacts on and let the computer show me the ship and it's course

.

But I don't want to do that. I like to figure it out myself, and it really is NOT hard at all.

In fact it's pretty easy. Draw a few lines and circles, wait, repeat, and boom, you have their heading. move, repeat, and you have their distance and speed. No calculations... no work... just drawing some lines, angles, and circles. The PDF's I made are just that - a simple (and easy to follow) step-by-step explanation of how to make the lines and circles.

/shrug anyway, I just think it is a blast to figure out where the target is (well beyond visual range), move to their course, set up, and then sit and quietly wait while they chug along into the firing lane

Now I patrol a bit, submerge, all stop, and wait... (TC++) that way I can pick up a contact as soon as they come into range - at max distance. Plot, intercept, and WHAM!!

Word of caution, it will work against a convoy, but unless you are tracking the EXACT same ship (each time you get the bearing), the course you plot will be off by a bit

. Still plenty close enough to get well in front of them, but you'll then need your scope to finish the firing solution

.

Also, the longer you wait between bearings - the farther apart the bearing lines are (in degrees) - the more accurate you'll be. Just don't wait too long or they'll sail right on past and out of range!!!

Placoderm · 04-08-10, 02:26 PM

This is AWESOME!

Thank you!!

Bothersome · 04-08-10, 04:00 PM

Hmm... OK you said in step 11.2 that I need to move my sub to a new position. But my sub won't go but 9 knots while submerged. How did you go faster than the target to overtake it even a little. And you calculated the target was moving 10 knots. Now what?

I think I'll stick with my approach.

Target detected at 0.00 (180 due south). Wait a couple of minutes and get bearing from sonar guy again. Notice it increased to 2. Turn sub to heading 270 speed set to full and wait 2 minutes. What is target bearing doing? I'm at 6 knots bearing holding steady at my 272. Steady as she goes for 5 minutes. New bearing, target at 270. Hold course and verify target is getting louder. If not, give up or run around it on surface. If it is getting closer, I'm already on intercept course (based on your example heading and speed). When target gets real close I use periscope to get set up for shot. If target was falling behind some then I slow and stop as bearing stops decreasing (I'm in front of it).

No fuss, no muss. And no lines and circles.

And, the main benefit. I don't have to race it. As I have put my sub in front of the target much earlier.

Granted, I won't be able to pull the trigger on the target WITHOUT using the scope. Your method might actually have a decent chance of finding bearing and speed and allow you to prepare a shot without ever seeing the target. Which I guess is needed in heavy rain and fog. But like I said, if I had to use your method in that example given, I'd never be able to overtake the target at step 11.2 to get set up for the shot.

ERPP8 · 04-08-10, 05:47 PM

You know Benno has a great skill called "Total revealing"

gutted · 04-08-10, 05:51 PM

Quote:

Originally Posted by ERPP8

You know Benno has a great skill called "Total revealing"

And you learn nothing from using it.....

timmy41 · 04-10-10, 05:47 PM

in step 4 you draw the 'NW line', but what if the contact is to the SE or NW? it will not work?

Pisces · 04-10-10, 07:14 PM

Quote:

Originally Posted by timmy41

in step 4 you draw the 'NW line', but what if the contact is to the SE or NW? it will not work?

Why wouldn't it? The bearings show where the target is (and was). In step 4 Alcibiades has just drawn a line in a random direction (well, from bearing 1 over to and across bearing 3). Look at step 5 to 8. Using the circle and line parallel to bearing 1 he corrected the NW line to the correct course. It doesn't matter where he comes from or it's actual course being totally different. The circle and parallel line will show if it is a wrong guess, and what the right course is.

Alcibiades · 04-10-10, 07:58 PM

Quote:

Originally Posted by Pisces

Why wouldn't it? The bearings show where the target is (and was). In step 4 Alcibiades has just drawn a line in a random direction (well, from bearing 1 over to and across bearing 3). Look at step 5 to 8. Using the circle and line parallel to bearing 1 he corrected the NW line to the correct course. It doesn't matter where he comes from or it's actual course being totally different. The circle and parallel line will show if it is a wrong guess, and what the right course is.

Yes.

The line in step 4 is just a random line (guess) to allow use of geometry to get the real heading.

Also, since you were sitting still and not moving from when you took bearing 1 until when you took bearing 3 - then you know that the target is moving towards the west. And you guess he's coming towards you.

If the target is E or N of you when you first pick him up, follow the same procedure, but just "guess" his route and assume he is 'slanting' towards you.

additional note: you can also tell he is coming towards you based on how much larger the angle is between bearing line 2 and 3. The larger that angle, the sharper angle the target is heading towards you. if the big angle is between lines 1 and 2 (and a small angle between bearing lines 2 and 3) then hes moving away!

Hope the PDF's help!

word of caution again: be careful if trying to use it against a convoy!!! if you record a different ship each time you listen (likely), then your estimates will be off. usually close enough to plot a rough intercept course, but that's probably about all

04-08-10, 01:24 PM	#3
gutted The Old Man Join Date: Apr 2005 Location: New Orleans, LA. Posts: 1,379 Downloads: 487 Uploads: 11	Ahem: http://www.subsim.com/radioroom/showthread.php?t=167103 ^ Once you lean the basics... you can stop drawing all those nasty lines. Post #12, shows a step by step using it. __________________ Solution Solver 2.3.2 - Visual Targeting Tools & Aids

04-08-10, 02:26 PM	#5
Placoderm Soundman Join Date: Apr 2005 Location: Arizona, USA Posts: 142 Downloads: 93 Uploads: 0	This is AWESOME! Thank you!! __________________ ....and on the eight day, god created merchant ships to ply the waters between the lands, and unto which was created a weakness to the holy torpedo so that man could blow thy living snot out of them. ...And all was good. "Making a decision to not make a decision would still involve a decision-making process and such a thing has not happened." -sorlim, UBIsoft Community Developer

04-08-10, 10:29 AM	#1
Alcibiades Watch Join Date: Apr 2010 Posts: 27 Downloads: 0 Uploads: 0	Hydrophone Hunting (tutorial) Hunting a target with the hydrophone. Using 100% realism (no map contacts) I asked for help with this a few days back and since have been having a blast with it. Picking up the sound of a target's 'whoop whoop' of the propeller well beyond visual range - plotting their course, moving to PERFECT intercept location.... all while well beyond visual range. Then waiting while they slowly come into view right along their pre-plotted "path" and into the sights, 500m away. Fun! Anyway, I made these two PDF files with 15 steps to illustrate how to track a ship with the hydrophones. I originally made them for myself, to help with understanding how it works - but figured I'd share them as they may be helpful for others. They are designed to be a simple step-by-step guide that can be easily printed. They require a basic understanding of how to use the drawing tools for in-game plotting. (edit) noticed some are missing S2. Be sure you download BOTH* sheets. The first (S-1) has steps 1-8 and plots heading. The second (S-2) has steps 9-15 and shows how to get speed and distance.* SHEET 1 http://www.filefront.com/16063311/Hy...cking%20S1.pdf and SHEET 2 http://www.filefront.com/16063315/Hy...cking%20S2.pdf Also, I sure as heck didn't invent this stuff - I just learned it a few days ago. Most helpful to me was the video by nefeldamon on the SHIII forum. I'd suggest checking it out also if you have the time. (the PDF files are based in concept around his example) http://www.subsim.com/radioroom/showthread.php?t=154461 And again big thanks to Kylania for pointing me to his video in the first place and also helping me find a site where I could upload the PDF files. Hope this is helpful to anyone else who may want to try this. Last edited by Alcibiades; 04-08-10 at 02:52 PM.

04-08-10, 11:25 AM	#2
Capt_Sluggo Watch Join Date: Apr 2010 Location: Costa Rica Posts: 30 Downloads: 13 Uploads: 0	Thank you, Alcibiades! This will be a lot of fun. Less dangerous than visual hunting, too.

04-08-10, 04:00 PM	#6
Bothersome Planesman Join Date: Mar 2010 Posts: 194 Downloads: 64 Uploads: 0	Hmm... OK you said in step 11.2 that I need to move my sub to a new position. But my sub won't go but 9 knots while submerged. How did you go faster than the target to overtake it even a little. And you calculated the target was moving 10 knots. Now what? I think I'll stick with my approach. Target detected at 0.00 (180 due south). Wait a couple of minutes and get bearing from sonar guy again. Notice it increased to 2. Turn sub to heading 270 speed set to full and wait 2 minutes. What is target bearing doing? I'm at 6 knots bearing holding steady at my 272. Steady as she goes for 5 minutes. New bearing, target at 270. Hold course and verify target is getting louder. If not, give up or run around it on surface. If it is getting closer, I'm already on intercept course (based on your example heading and speed). When target gets real close I use periscope to get set up for shot. If target was falling behind some then I slow and stop as bearing stops decreasing (I'm in front of it). No fuss, no muss. And no lines and circles. And, the main benefit. I don't have to race it. As I have put my sub in front of the target much earlier. Granted, I won't be able to pull the trigger on the target WITHOUT using the scope. Your method might actually have a decent chance of finding bearing and speed and allow you to prepare a shot without ever seeing the target. Which I guess is needed in heavy rain and fog. But like I said, if I had to use your method in that example given, I'd never be able to overtake the target at step 11.2 to get set up for the shot.

04-08-10, 05:47 PM	#7
ERPP8 Commodore Join Date: Dec 2009 Location: My House Posts: 608 Downloads: 161 Uploads: 0	You know Benno has a great skill called "Total revealing"

04-10-10, 05:47 PM	#9
timmy41 Weps Join Date: Mar 2010 Posts: 367 Downloads: 9 Uploads: 0	in step 4 you draw the 'NW line', but what if the contact is to the SE or NW? it will not work?